From mboxrd@z Thu Jan  1 00:00:00 1970
From: Clemens Ladisch <clemens@ladisch.de>
Subject: Re: [PATCH 0/2] Add support for Qualcomm's PRNG
Date: Fri, 11 Oct 2013 09:05:04 +0200
Message-ID: <5257A320.1070207@ladisch.de>
References: <1380811955-18085-1-git-send-email-svarbanov@mm-sol.com> <20131003165130.GA11974@thunk.org> <524EEB96.6040707@mm-sol.com> <20131004181005.GA7022@thunk.org> <52556C4E.9000604@mm-sol.com> <52557137.5050200@zytor.com> <5256AFFE.5090605@mm-sol.com>
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To: Stanimir Varbanov <svarbanov@mm-sol.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Theodore Ts'o <tytso@mit.edu>, Rob Herring <rob.herring@calxeda.com>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Stephen Warren <swarren@wwwdotorg.org>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Matt Mackall <mpm@selenic.com>, Herbert Xu <herbert@gondor.hengli.com.au>, linux-kernel@vger.kernel.org, Rob Landley <rob@landley.net>, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-arm-msm@vger.kernel.org
List-Id: linux-arm-msm@vger.kernel.org

Stanimir Varbanov wrote:
> I ran the rngtest with following command line:
>
> # cat /dev/hw_random | rngtest -c 100000
> ...
> rngtest: bits received from input: 2000000032
> rngtest: FIPS 140-2 successes: 99925
> rngtest: FIPS 140-2 failures: 75
> ...
>
> Could you guys comment those results?

These tests are expected to fail a few times even for perfectly random
data (think monkeys/Shakespeare).  An entropy source will be permanently
disabled by rngd only if the failure ratio is worse than 1 in 1000.


Regards,
Clemens